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1/*
2 * Copyright (c) 2006-2008 Intel Corporation
3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
4 *
5 * DRM core CRTC related functions
6 *
7 * Permission to use, copy, modify, distribute, and sell this software and its
8 * documentation for any purpose is hereby granted without fee, provided that
9 * the above copyright notice appear in all copies and that both that copyright
10 * notice and this permission notice appear in supporting documentation, and
11 * that the name of the copyright holders not be used in advertising or
12 * publicity pertaining to distribution of the software without specific,
13 * written prior permission. The copyright holders make no representations
14 * about the suitability of this software for any purpose. It is provided "as
15 * is" without express or implied warranty.
16 *
17 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
19 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
20 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
21 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
22 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 * OF THIS SOFTWARE.
24 *
25 * Authors:
26 * Keith Packard
27 * Eric Anholt <eric@anholt.net>
28 * Dave Airlie <airlied@linux.ie>
29 * Jesse Barnes <jesse.barnes@intel.com>
30 */
31
32#include <linux/export.h>
33#include <linux/moduleparam.h>
34
35#include <drm/drm_bridge.h>
36#include <drm/drm_client.h>
37#include <drm/drm_crtc.h>
38#include <drm/drm_edid.h>
39#include <drm/drm_fourcc.h>
40#include <drm/drm_modeset_helper_vtables.h>
41#include <drm/drm_print.h>
42#include <drm/drm_probe_helper.h>
43#include <drm/drm_sysfs.h>
44
45#include "drm_crtc_helper_internal.h"
46
47/**
48 * DOC: output probing helper overview
49 *
50 * This library provides some helper code for output probing. It provides an
51 * implementation of the core &drm_connector_funcs.fill_modes interface with
52 * drm_helper_probe_single_connector_modes().
53 *
54 * It also provides support for polling connectors with a work item and for
55 * generic hotplug interrupt handling where the driver doesn't or cannot keep
56 * track of a per-connector hpd interrupt.
57 *
58 * This helper library can be used independently of the modeset helper library.
59 * Drivers can also overwrite different parts e.g. use their own hotplug
60 * handling code to avoid probing unrelated outputs.
61 *
62 * The probe helpers share the function table structures with other display
63 * helper libraries. See &struct drm_connector_helper_funcs for the details.
64 */
65
66static bool drm_kms_helper_poll = true;
67module_param_named(poll, drm_kms_helper_poll, bool, 0600);
68
69static enum drm_mode_status
70drm_mode_validate_flag(const struct drm_display_mode *mode,
71 int flags)
72{
73 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
74 !(flags & DRM_MODE_FLAG_INTERLACE))
75 return MODE_NO_INTERLACE;
76
77 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
78 !(flags & DRM_MODE_FLAG_DBLSCAN))
79 return MODE_NO_DBLESCAN;
80
81 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
82 !(flags & DRM_MODE_FLAG_3D_MASK))
83 return MODE_NO_STEREO;
84
85 return MODE_OK;
86}
87
88static int
89drm_mode_validate_pipeline(struct drm_display_mode *mode,
90 struct drm_connector *connector,
91 struct drm_modeset_acquire_ctx *ctx,
92 enum drm_mode_status *status)
93{
94 struct drm_device *dev = connector->dev;
95 struct drm_encoder *encoder;
96 int ret;
97
98 /* Step 1: Validate against connector */
99 ret = drm_connector_mode_valid(connector, mode, ctx, status);
100 if (ret || *status != MODE_OK)
101 return ret;
102
103 /* Step 2: Validate against encoders and crtcs */
104 drm_connector_for_each_possible_encoder(connector, encoder) {
105 struct drm_bridge *bridge;
106 struct drm_crtc *crtc;
107
108 *status = drm_encoder_mode_valid(encoder, mode);
109 if (*status != MODE_OK) {
110 /* No point in continuing for crtc check as this encoder
111 * will not accept the mode anyway. If all encoders
112 * reject the mode then, at exit, ret will not be
113 * MODE_OK. */
114 continue;
115 }
116
117 bridge = drm_bridge_chain_get_first_bridge(encoder);
118 *status = drm_bridge_chain_mode_valid(bridge,
119 &connector->display_info,
120 mode);
121 if (*status != MODE_OK) {
122 /* There is also no point in continuing for crtc check
123 * here. */
124 continue;
125 }
126
127 drm_for_each_crtc(crtc, dev) {
128 if (!drm_encoder_crtc_ok(encoder, crtc))
129 continue;
130
131 *status = drm_crtc_mode_valid(crtc, mode);
132 if (*status == MODE_OK) {
133 /* If we get to this point there is at least
134 * one combination of encoder+crtc that works
135 * for this mode. Lets return now. */
136 return 0;
137 }
138 }
139 }
140
141 return 0;
142}
143
144static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
145{
146 struct drm_cmdline_mode *cmdline_mode;
147 struct drm_display_mode *mode;
148
149 cmdline_mode = &connector->cmdline_mode;
150 if (!cmdline_mode->specified)
151 return 0;
152
153 /* Only add a GTF mode if we find no matching probed modes */
154 list_for_each_entry(mode, &connector->probed_modes, head) {
155 if (mode->hdisplay != cmdline_mode->xres ||
156 mode->vdisplay != cmdline_mode->yres)
157 continue;
158
159 if (cmdline_mode->refresh_specified) {
160 /* The probed mode's vrefresh is set until later */
161 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
162 continue;
163 }
164
165 /* Mark the matching mode as being preferred by the user */
166 mode->type |= DRM_MODE_TYPE_USERDEF;
167 return 0;
168 }
169
170 mode = drm_mode_create_from_cmdline_mode(connector->dev,
171 cmdline_mode);
172 if (mode == NULL)
173 return 0;
174
175 drm_mode_probed_add(connector, mode);
176 return 1;
177}
178
179enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
180 const struct drm_display_mode *mode)
181{
182 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
183
184 if (!crtc_funcs || !crtc_funcs->mode_valid)
185 return MODE_OK;
186
187 return crtc_funcs->mode_valid(crtc, mode);
188}
189
190enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
191 const struct drm_display_mode *mode)
192{
193 const struct drm_encoder_helper_funcs *encoder_funcs =
194 encoder->helper_private;
195
196 if (!encoder_funcs || !encoder_funcs->mode_valid)
197 return MODE_OK;
198
199 return encoder_funcs->mode_valid(encoder, mode);
200}
201
202int
203drm_connector_mode_valid(struct drm_connector *connector,
204 struct drm_display_mode *mode,
205 struct drm_modeset_acquire_ctx *ctx,
206 enum drm_mode_status *status)
207{
208 const struct drm_connector_helper_funcs *connector_funcs =
209 connector->helper_private;
210 int ret = 0;
211
212 if (!connector_funcs)
213 *status = MODE_OK;
214 else if (connector_funcs->mode_valid_ctx)
215 ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
216 status);
217 else if (connector_funcs->mode_valid)
218 *status = connector_funcs->mode_valid(connector, mode);
219 else
220 *status = MODE_OK;
221
222 return ret;
223}
224
225static void drm_kms_helper_disable_hpd(struct drm_device *dev)
226{
227 struct drm_connector *connector;
228 struct drm_connector_list_iter conn_iter;
229
230 drm_connector_list_iter_begin(dev, &conn_iter);
231 drm_for_each_connector_iter(connector, &conn_iter) {
232 const struct drm_connector_helper_funcs *funcs =
233 connector->helper_private;
234
235 if (funcs && funcs->disable_hpd)
236 funcs->disable_hpd(connector);
237 }
238 drm_connector_list_iter_end(&conn_iter);
239}
240
241static bool drm_kms_helper_enable_hpd(struct drm_device *dev)
242{
243 bool poll = false;
244 struct drm_connector *connector;
245 struct drm_connector_list_iter conn_iter;
246
247 drm_connector_list_iter_begin(dev, &conn_iter);
248 drm_for_each_connector_iter(connector, &conn_iter) {
249 const struct drm_connector_helper_funcs *funcs =
250 connector->helper_private;
251
252 if (funcs && funcs->enable_hpd)
253 funcs->enable_hpd(connector);
254
255 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
256 DRM_CONNECTOR_POLL_DISCONNECT))
257 poll = true;
258 }
259 drm_connector_list_iter_end(&conn_iter);
260
261 return poll;
262}
263
264#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
265static void reschedule_output_poll_work(struct drm_device *dev)
266{
267 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
268
269 if (dev->mode_config.delayed_event)
270 /*
271 * FIXME:
272 *
273 * Use short (1s) delay to handle the initial delayed event.
274 * This delay should not be needed, but Optimus/nouveau will
275 * fail in a mysterious way if the delayed event is handled as
276 * soon as possible like it is done in
277 * drm_helper_probe_single_connector_modes() in case the poll
278 * was enabled before.
279 */
280 delay = HZ;
281
282 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
283}
284
285/**
286 * drm_kms_helper_poll_enable - re-enable output polling.
287 * @dev: drm_device
288 *
289 * This function re-enables the output polling work, after it has been
290 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
291 * suspend/resume.
292 *
293 * Drivers can call this helper from their device resume implementation. It is
294 * not an error to call this even when output polling isn't enabled.
295 *
296 * Note that calls to enable and disable polling must be strictly ordered, which
297 * is automatically the case when they're only call from suspend/resume
298 * callbacks.
299 */
300void drm_kms_helper_poll_enable(struct drm_device *dev)
301{
302 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll ||
303 dev->mode_config.poll_running)
304 return;
305
306 if (drm_kms_helper_enable_hpd(dev) ||
307 dev->mode_config.delayed_event)
308 reschedule_output_poll_work(dev);
309
310 dev->mode_config.poll_running = true;
311}
312EXPORT_SYMBOL(drm_kms_helper_poll_enable);
313
314/**
315 * drm_kms_helper_poll_reschedule - reschedule the output polling work
316 * @dev: drm_device
317 *
318 * This function reschedules the output polling work, after polling for a
319 * connector has been enabled.
320 *
321 * Drivers must call this helper after enabling polling for a connector by
322 * setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags
323 * in drm_connector::polled. Note that after disabling polling by clearing these
324 * flags for a connector will stop the output polling work automatically if
325 * the polling is disabled for all other connectors as well.
326 *
327 * The function can be called only after polling has been enabled by calling
328 * drm_kms_helper_poll_init() / drm_kms_helper_poll_enable().
329 */
330void drm_kms_helper_poll_reschedule(struct drm_device *dev)
331{
332 if (dev->mode_config.poll_running)
333 reschedule_output_poll_work(dev);
334}
335EXPORT_SYMBOL(drm_kms_helper_poll_reschedule);
336
337static enum drm_connector_status
338drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
339{
340 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
341 struct drm_modeset_acquire_ctx ctx;
342 int ret;
343
344 drm_modeset_acquire_init(&ctx, 0);
345
346retry:
347 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
348 if (!ret) {
349 if (funcs->detect_ctx)
350 ret = funcs->detect_ctx(connector, &ctx, force);
351 else if (connector->funcs->detect)
352 ret = connector->funcs->detect(connector, force);
353 else
354 ret = connector_status_connected;
355 }
356
357 if (ret == -EDEADLK) {
358 drm_modeset_backoff(&ctx);
359 goto retry;
360 }
361
362 if (WARN_ON(ret < 0))
363 ret = connector_status_unknown;
364
365 if (ret != connector->status)
366 connector->epoch_counter += 1;
367
368 drm_modeset_drop_locks(&ctx);
369 drm_modeset_acquire_fini(&ctx);
370
371 return ret;
372}
373
374/**
375 * drm_helper_probe_detect - probe connector status
376 * @connector: connector to probe
377 * @ctx: acquire_ctx, or NULL to let this function handle locking.
378 * @force: Whether destructive probe operations should be performed.
379 *
380 * This function calls the detect callbacks of the connector.
381 * This function returns &drm_connector_status, or
382 * if @ctx is set, it might also return -EDEADLK.
383 */
384int
385drm_helper_probe_detect(struct drm_connector *connector,
386 struct drm_modeset_acquire_ctx *ctx,
387 bool force)
388{
389 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
390 struct drm_device *dev = connector->dev;
391 int ret;
392
393 if (!ctx)
394 return drm_helper_probe_detect_ctx(connector, force);
395
396 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
397 if (ret)
398 return ret;
399
400 if (funcs->detect_ctx)
401 ret = funcs->detect_ctx(connector, ctx, force);
402 else if (connector->funcs->detect)
403 ret = connector->funcs->detect(connector, force);
404 else
405 ret = connector_status_connected;
406
407 if (ret != connector->status)
408 connector->epoch_counter += 1;
409
410 return ret;
411}
412EXPORT_SYMBOL(drm_helper_probe_detect);
413
414static int drm_helper_probe_get_modes(struct drm_connector *connector)
415{
416 const struct drm_connector_helper_funcs *connector_funcs =
417 connector->helper_private;
418 int count;
419
420 count = connector_funcs->get_modes(connector);
421
422 /*
423 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
424 * override/firmware EDID.
425 */
426 if (count == 0 && connector->status == connector_status_connected)
427 count = drm_edid_override_connector_update(connector);
428
429 return count;
430}
431
432static int __drm_helper_update_and_validate(struct drm_connector *connector,
433 uint32_t maxX, uint32_t maxY,
434 struct drm_modeset_acquire_ctx *ctx)
435{
436 struct drm_device *dev = connector->dev;
437 struct drm_display_mode *mode;
438 int mode_flags = 0;
439 int ret;
440
441 drm_connector_list_update(connector);
442
443 if (connector->interlace_allowed)
444 mode_flags |= DRM_MODE_FLAG_INTERLACE;
445 if (connector->doublescan_allowed)
446 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
447 if (connector->stereo_allowed)
448 mode_flags |= DRM_MODE_FLAG_3D_MASK;
449
450 list_for_each_entry(mode, &connector->modes, head) {
451 if (mode->status != MODE_OK)
452 continue;
453
454 mode->status = drm_mode_validate_driver(dev, mode);
455 if (mode->status != MODE_OK)
456 continue;
457
458 mode->status = drm_mode_validate_size(mode, maxX, maxY);
459 if (mode->status != MODE_OK)
460 continue;
461
462 mode->status = drm_mode_validate_flag(mode, mode_flags);
463 if (mode->status != MODE_OK)
464 continue;
465
466 ret = drm_mode_validate_pipeline(mode, connector, ctx,
467 &mode->status);
468 if (ret) {
469 drm_dbg_kms(dev,
470 "drm_mode_validate_pipeline failed: %d\n",
471 ret);
472
473 if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK))
474 mode->status = MODE_ERROR;
475 else
476 return -EDEADLK;
477 }
478
479 if (mode->status != MODE_OK)
480 continue;
481 mode->status = drm_mode_validate_ycbcr420(mode, connector);
482 }
483
484 return 0;
485}
486
487/**
488 * drm_helper_probe_single_connector_modes - get complete set of display modes
489 * @connector: connector to probe
490 * @maxX: max width for modes
491 * @maxY: max height for modes
492 *
493 * Based on the helper callbacks implemented by @connector in struct
494 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
495 * be added to the connector's probed_modes list, then culled (based on validity
496 * and the @maxX, @maxY parameters) and put into the normal modes list.
497 *
498 * Intended to be used as a generic implementation of the
499 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
500 * for output mode filtering and detection.
501 *
502 * The basic procedure is as follows
503 *
504 * 1. All modes currently on the connector's modes list are marked as stale
505 *
506 * 2. New modes are added to the connector's probed_modes list with
507 * drm_mode_probed_add(). New modes start their life with status as OK.
508 * Modes are added from a single source using the following priority order.
509 *
510 * - &drm_connector_helper_funcs.get_modes vfunc
511 * - if the connector status is connector_status_connected, standard
512 * VESA DMT modes up to 1024x768 are automatically added
513 * (drm_add_modes_noedid())
514 *
515 * Finally modes specified via the kernel command line (video=...) are
516 * added in addition to what the earlier probes produced
517 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
518 * using the VESA GTF/CVT formulas.
519 *
520 * 3. Modes are moved from the probed_modes list to the modes list. Potential
521 * duplicates are merged together (see drm_connector_list_update()).
522 * After this step the probed_modes list will be empty again.
523 *
524 * 4. Any non-stale mode on the modes list then undergoes validation
525 *
526 * - drm_mode_validate_basic() performs basic sanity checks
527 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
528 * (if specified)
529 * - drm_mode_validate_flag() checks the modes against basic connector
530 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
531 * - the optional &drm_connector_helper_funcs.mode_valid or
532 * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
533 * and/or sink specific checks
534 * - the optional &drm_crtc_helper_funcs.mode_valid,
535 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
536 * helpers can perform driver and/or source specific checks which are also
537 * enforced by the modeset/atomic helpers
538 *
539 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
540 * accompanied by a debug message indicating the reason for the mode's
541 * rejection (see drm_mode_prune_invalid()).
542 *
543 * Returns:
544 * The number of modes found on @connector.
545 */
546int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
547 uint32_t maxX, uint32_t maxY)
548{
549 struct drm_device *dev = connector->dev;
550 struct drm_display_mode *mode;
551 int count = 0, ret;
552 enum drm_connector_status old_status;
553 struct drm_modeset_acquire_ctx ctx;
554
555 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
556
557 drm_modeset_acquire_init(&ctx, 0);
558
559 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
560 connector->name);
561
562retry:
563 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
564 if (ret == -EDEADLK) {
565 drm_modeset_backoff(&ctx);
566 goto retry;
567 } else
568 WARN_ON(ret < 0);
569
570 /* set all old modes to the stale state */
571 list_for_each_entry(mode, &connector->modes, head)
572 mode->status = MODE_STALE;
573
574 old_status = connector->status;
575
576 if (connector->force) {
577 if (connector->force == DRM_FORCE_ON ||
578 connector->force == DRM_FORCE_ON_DIGITAL)
579 connector->status = connector_status_connected;
580 else
581 connector->status = connector_status_disconnected;
582 if (connector->funcs->force)
583 connector->funcs->force(connector);
584 } else {
585 ret = drm_helper_probe_detect(connector, &ctx, true);
586
587 if (ret == -EDEADLK) {
588 drm_modeset_backoff(&ctx);
589 goto retry;
590 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
591 ret = connector_status_unknown;
592
593 connector->status = ret;
594 }
595
596 /*
597 * Normally either the driver's hpd code or the poll loop should
598 * pick up any changes and fire the hotplug event. But if
599 * userspace sneaks in a probe, we might miss a change. Hence
600 * check here, and if anything changed start the hotplug code.
601 */
602 if (old_status != connector->status) {
603 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
604 connector->base.id,
605 connector->name,
606 drm_get_connector_status_name(old_status),
607 drm_get_connector_status_name(connector->status));
608
609 /*
610 * The hotplug event code might call into the fb
611 * helpers, and so expects that we do not hold any
612 * locks. Fire up the poll struct instead, it will
613 * disable itself again.
614 */
615 dev->mode_config.delayed_event = true;
616 if (dev->mode_config.poll_enabled)
617 mod_delayed_work(system_wq,
618 &dev->mode_config.output_poll_work,
619 0);
620 }
621
622 /* Re-enable polling in case the global poll config changed. */
623 drm_kms_helper_poll_enable(dev);
624
625 if (connector->status == connector_status_disconnected) {
626 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
627 connector->base.id, connector->name);
628 drm_connector_update_edid_property(connector, NULL);
629 drm_mode_prune_invalid(dev, &connector->modes, false);
630 goto exit;
631 }
632
633 count = drm_helper_probe_get_modes(connector);
634
635 if (count == 0 && (connector->status == connector_status_connected ||
636 connector->status == connector_status_unknown)) {
637 count = drm_add_modes_noedid(connector, 1024, 768);
638
639 /*
640 * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
641 * Link CTS specifies that 640x480 (the official "failsafe"
642 * mode) needs to be the default if there's no EDID.
643 */
644 if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort)
645 drm_set_preferred_mode(connector, 640, 480);
646 }
647 count += drm_helper_probe_add_cmdline_mode(connector);
648 if (count != 0) {
649 ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
650 if (ret == -EDEADLK) {
651 drm_modeset_backoff(&ctx);
652 goto retry;
653 }
654 }
655
656 drm_mode_prune_invalid(dev, &connector->modes, true);
657
658 /*
659 * Displayport spec section 5.2.1.2 ("Video Timing Format") says that
660 * all detachable sinks shall support 640x480 @60Hz as a fail safe
661 * mode. If all modes were pruned, perhaps because they need more
662 * lanes or a higher pixel clock than available, at least try to add
663 * in 640x480.
664 */
665 if (list_empty(&connector->modes) &&
666 connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
667 count = drm_add_modes_noedid(connector, 640, 480);
668 ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
669 if (ret == -EDEADLK) {
670 drm_modeset_backoff(&ctx);
671 goto retry;
672 }
673 drm_mode_prune_invalid(dev, &connector->modes, true);
674 }
675
676exit:
677 drm_modeset_drop_locks(&ctx);
678 drm_modeset_acquire_fini(&ctx);
679
680 if (list_empty(&connector->modes))
681 return 0;
682
683 drm_mode_sort(&connector->modes);
684
685 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
686 connector->name);
687 list_for_each_entry(mode, &connector->modes, head) {
688 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
689 drm_mode_debug_printmodeline(mode);
690 }
691
692 return count;
693}
694EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
695
696/**
697 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
698 * @dev: drm_device whose connector state changed
699 *
700 * This function fires off the uevent for userspace and also calls the
701 * output_poll_changed function, which is most commonly used to inform the fbdev
702 * emulation code and allow it to update the fbcon output configuration.
703 *
704 * Drivers should call this from their hotplug handling code when a change is
705 * detected. Note that this function does not do any output detection of its
706 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
707 * driver already.
708 *
709 * This function must be called from process context with no mode
710 * setting locks held.
711 *
712 * If only a single connector has changed, consider calling
713 * drm_kms_helper_connector_hotplug_event() instead.
714 */
715void drm_kms_helper_hotplug_event(struct drm_device *dev)
716{
717 /* send a uevent + call fbdev */
718 drm_sysfs_hotplug_event(dev);
719 if (dev->mode_config.funcs->output_poll_changed)
720 dev->mode_config.funcs->output_poll_changed(dev);
721
722 drm_client_dev_hotplug(dev);
723}
724EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
725
726/**
727 * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
728 * @connector: drm_connector which has changed
729 *
730 * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
731 * fine-grained uevent for a single connector.
732 */
733void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
734{
735 struct drm_device *dev = connector->dev;
736
737 /* send a uevent + call fbdev */
738 drm_sysfs_connector_hotplug_event(connector);
739 if (dev->mode_config.funcs->output_poll_changed)
740 dev->mode_config.funcs->output_poll_changed(dev);
741
742 drm_client_dev_hotplug(dev);
743}
744EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
745
746static void output_poll_execute(struct work_struct *work)
747{
748 struct delayed_work *delayed_work = to_delayed_work(work);
749 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
750 struct drm_connector *connector;
751 struct drm_connector_list_iter conn_iter;
752 enum drm_connector_status old_status;
753 bool repoll = false, changed;
754 u64 old_epoch_counter;
755
756 if (!dev->mode_config.poll_enabled)
757 return;
758
759 /* Pick up any changes detected by the probe functions. */
760 changed = dev->mode_config.delayed_event;
761 dev->mode_config.delayed_event = false;
762
763 if (!drm_kms_helper_poll) {
764 if (dev->mode_config.poll_running) {
765 drm_kms_helper_disable_hpd(dev);
766 dev->mode_config.poll_running = false;
767 }
768 goto out;
769 }
770
771 if (!mutex_trylock(&dev->mode_config.mutex)) {
772 repoll = true;
773 goto out;
774 }
775
776 drm_connector_list_iter_begin(dev, &conn_iter);
777 drm_for_each_connector_iter(connector, &conn_iter) {
778 /* Ignore forced connectors. */
779 if (connector->force)
780 continue;
781
782 /* Ignore HPD capable connectors and connectors where we don't
783 * want any hotplug detection at all for polling. */
784 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
785 continue;
786
787 old_status = connector->status;
788 /* if we are connected and don't want to poll for disconnect
789 skip it */
790 if (old_status == connector_status_connected &&
791 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
792 continue;
793
794 repoll = true;
795
796 old_epoch_counter = connector->epoch_counter;
797 connector->status = drm_helper_probe_detect(connector, NULL, false);
798 if (old_epoch_counter != connector->epoch_counter) {
799 const char *old, *new;
800
801 /*
802 * The poll work sets force=false when calling detect so
803 * that drivers can avoid to do disruptive tests (e.g.
804 * when load detect cycles could cause flickering on
805 * other, running displays). This bears the risk that we
806 * flip-flop between unknown here in the poll work and
807 * the real state when userspace forces a full detect
808 * call after receiving a hotplug event due to this
809 * change.
810 *
811 * Hence clamp an unknown detect status to the old
812 * value.
813 */
814 if (connector->status == connector_status_unknown) {
815 connector->status = old_status;
816 continue;
817 }
818
819 old = drm_get_connector_status_name(old_status);
820 new = drm_get_connector_status_name(connector->status);
821
822 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
823 "status updated from %s to %s\n",
824 connector->base.id,
825 connector->name,
826 old, new);
827 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
828 connector->base.id, connector->name,
829 old_epoch_counter, connector->epoch_counter);
830
831 changed = true;
832 }
833 }
834 drm_connector_list_iter_end(&conn_iter);
835
836 mutex_unlock(&dev->mode_config.mutex);
837
838out:
839 if (changed)
840 drm_kms_helper_hotplug_event(dev);
841
842 if (repoll)
843 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
844}
845
846/**
847 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
848 *
849 * Determine if %current task is an output poll worker. This can be used
850 * to select distinct code paths for output polling versus other contexts.
851 *
852 * One use case is to avoid a deadlock between the output poll worker and
853 * the autosuspend worker wherein the latter waits for polling to finish
854 * upon calling drm_kms_helper_poll_disable(), while the former waits for
855 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
856 * connector ->detect hook.
857 */
858bool drm_kms_helper_is_poll_worker(void)
859{
860 struct work_struct *work = current_work();
861
862 return work && work->func == output_poll_execute;
863}
864EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
865
866/**
867 * drm_kms_helper_poll_disable - disable output polling
868 * @dev: drm_device
869 *
870 * This function disables the output polling work.
871 *
872 * Drivers can call this helper from their device suspend implementation. It is
873 * not an error to call this even when output polling isn't enabled or already
874 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
875 *
876 * Note that calls to enable and disable polling must be strictly ordered, which
877 * is automatically the case when they're only call from suspend/resume
878 * callbacks.
879 */
880void drm_kms_helper_poll_disable(struct drm_device *dev)
881{
882 if (dev->mode_config.poll_running)
883 drm_kms_helper_disable_hpd(dev);
884
885 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
886
887 dev->mode_config.poll_running = false;
888}
889EXPORT_SYMBOL(drm_kms_helper_poll_disable);
890
891/**
892 * drm_kms_helper_poll_init - initialize and enable output polling
893 * @dev: drm_device
894 *
895 * This function initializes and then also enables output polling support for
896 * @dev. Drivers which do not have reliable hotplug support in hardware can use
897 * this helper infrastructure to regularly poll such connectors for changes in
898 * their connection state.
899 *
900 * Drivers can control which connectors are polled by setting the
901 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
902 * connectors where probing live outputs can result in visual distortion drivers
903 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
904 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
905 * completely ignored by the polling logic.
906 *
907 * Note that a connector can be both polled and probed from the hotplug handler,
908 * in case the hotplug interrupt is known to be unreliable.
909 */
910void drm_kms_helper_poll_init(struct drm_device *dev)
911{
912 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
913 dev->mode_config.poll_enabled = true;
914
915 drm_kms_helper_poll_enable(dev);
916}
917EXPORT_SYMBOL(drm_kms_helper_poll_init);
918
919/**
920 * drm_kms_helper_poll_fini - disable output polling and clean it up
921 * @dev: drm_device
922 */
923void drm_kms_helper_poll_fini(struct drm_device *dev)
924{
925 if (!dev->mode_config.poll_enabled)
926 return;
927
928 drm_kms_helper_poll_disable(dev);
929
930 dev->mode_config.poll_enabled = false;
931}
932EXPORT_SYMBOL(drm_kms_helper_poll_fini);
933
934static bool check_connector_changed(struct drm_connector *connector)
935{
936 struct drm_device *dev = connector->dev;
937 enum drm_connector_status old_status;
938 u64 old_epoch_counter;
939
940 /* Only handle HPD capable connectors. */
941 drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
942
943 drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
944
945 old_status = connector->status;
946 old_epoch_counter = connector->epoch_counter;
947 connector->status = drm_helper_probe_detect(connector, NULL, false);
948
949 if (old_epoch_counter == connector->epoch_counter) {
950 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
951 connector->base.id,
952 connector->name,
953 connector->epoch_counter);
954
955 return false;
956 }
957
958 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
959 connector->base.id,
960 connector->name,
961 drm_get_connector_status_name(old_status),
962 drm_get_connector_status_name(connector->status));
963
964 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
965 connector->base.id,
966 connector->name,
967 old_epoch_counter,
968 connector->epoch_counter);
969
970 return true;
971}
972
973/**
974 * drm_connector_helper_hpd_irq_event - hotplug processing
975 * @connector: drm_connector
976 *
977 * Drivers can use this helper function to run a detect cycle on a connector
978 * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
979 *
980 * This helper function is useful for drivers which can track hotplug
981 * interrupts for a single connector. Drivers that want to send a
982 * hotplug event for all connectors or can't track hotplug interrupts
983 * per connector need to use drm_helper_hpd_irq_event().
984 *
985 * This function must be called from process context with no mode
986 * setting locks held.
987 *
988 * Note that a connector can be both polled and probed from the hotplug
989 * handler, in case the hotplug interrupt is known to be unreliable.
990 *
991 * Returns:
992 * A boolean indicating whether the connector status changed or not
993 */
994bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
995{
996 struct drm_device *dev = connector->dev;
997 bool changed;
998
999 mutex_lock(&dev->mode_config.mutex);
1000 changed = check_connector_changed(connector);
1001 mutex_unlock(&dev->mode_config.mutex);
1002
1003 if (changed) {
1004 drm_kms_helper_connector_hotplug_event(connector);
1005 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
1006 connector->base.id,
1007 connector->name);
1008 }
1009
1010 return changed;
1011}
1012EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
1013
1014/**
1015 * drm_helper_hpd_irq_event - hotplug processing
1016 * @dev: drm_device
1017 *
1018 * Drivers can use this helper function to run a detect cycle on all connectors
1019 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
1020 * other connectors are ignored, which is useful to avoid reprobing fixed
1021 * panels.
1022 *
1023 * This helper function is useful for drivers which can't or don't track hotplug
1024 * interrupts for each connector.
1025 *
1026 * Drivers which support hotplug interrupts for each connector individually and
1027 * which have a more fine-grained detect logic can use
1028 * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
1029 * code and directly call drm_kms_helper_hotplug_event() in case the connector
1030 * state changed.
1031 *
1032 * This function must be called from process context with no mode
1033 * setting locks held.
1034 *
1035 * Note that a connector can be both polled and probed from the hotplug handler,
1036 * in case the hotplug interrupt is known to be unreliable.
1037 *
1038 * Returns:
1039 * A boolean indicating whether the connector status changed or not
1040 */
1041bool drm_helper_hpd_irq_event(struct drm_device *dev)
1042{
1043 struct drm_connector *connector, *first_changed_connector = NULL;
1044 struct drm_connector_list_iter conn_iter;
1045 int changed = 0;
1046
1047 if (!dev->mode_config.poll_enabled)
1048 return false;
1049
1050 mutex_lock(&dev->mode_config.mutex);
1051 drm_connector_list_iter_begin(dev, &conn_iter);
1052 drm_for_each_connector_iter(connector, &conn_iter) {
1053 /* Only handle HPD capable connectors. */
1054 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
1055 continue;
1056
1057 if (check_connector_changed(connector)) {
1058 if (!first_changed_connector) {
1059 drm_connector_get(connector);
1060 first_changed_connector = connector;
1061 }
1062
1063 changed++;
1064 }
1065 }
1066 drm_connector_list_iter_end(&conn_iter);
1067 mutex_unlock(&dev->mode_config.mutex);
1068
1069 if (changed == 1)
1070 drm_kms_helper_connector_hotplug_event(first_changed_connector);
1071 else if (changed > 0)
1072 drm_kms_helper_hotplug_event(dev);
1073
1074 if (first_changed_connector)
1075 drm_connector_put(first_changed_connector);
1076
1077 return changed;
1078}
1079EXPORT_SYMBOL(drm_helper_hpd_irq_event);
1080
1081/**
1082 * drm_crtc_helper_mode_valid_fixed - Validates a display mode
1083 * @crtc: the crtc
1084 * @mode: the mode to validate
1085 * @fixed_mode: the display hardware's mode
1086 *
1087 * Returns:
1088 * MODE_OK on success, or another mode-status code otherwise.
1089 */
1090enum drm_mode_status drm_crtc_helper_mode_valid_fixed(struct drm_crtc *crtc,
1091 const struct drm_display_mode *mode,
1092 const struct drm_display_mode *fixed_mode)
1093{
1094 if (mode->hdisplay != fixed_mode->hdisplay && mode->vdisplay != fixed_mode->vdisplay)
1095 return MODE_ONE_SIZE;
1096 else if (mode->hdisplay != fixed_mode->hdisplay)
1097 return MODE_ONE_WIDTH;
1098 else if (mode->vdisplay != fixed_mode->vdisplay)
1099 return MODE_ONE_HEIGHT;
1100
1101 return MODE_OK;
1102}
1103EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed);
1104
1105/**
1106 * drm_connector_helper_get_modes_from_ddc - Updates the connector's EDID
1107 * property from the connector's
1108 * DDC channel
1109 * @connector: The connector
1110 *
1111 * Returns:
1112 * The number of detected display modes.
1113 *
1114 * Uses a connector's DDC channel to retrieve EDID data and update the
1115 * connector's EDID property and display modes. Drivers can use this
1116 * function to implement struct &drm_connector_helper_funcs.get_modes
1117 * for connectors with a DDC channel.
1118 */
1119int drm_connector_helper_get_modes_from_ddc(struct drm_connector *connector)
1120{
1121 struct edid *edid;
1122 int count = 0;
1123
1124 if (!connector->ddc)
1125 return 0;
1126
1127 edid = drm_get_edid(connector, connector->ddc);
1128
1129 // clears property if EDID is NULL
1130 drm_connector_update_edid_property(connector, edid);
1131
1132 if (edid) {
1133 count = drm_add_edid_modes(connector, edid);
1134 kfree(edid);
1135 }
1136
1137 return count;
1138}
1139EXPORT_SYMBOL(drm_connector_helper_get_modes_from_ddc);
1140
1141/**
1142 * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector
1143 * @connector: the connector
1144 * @fixed_mode: the display hardware's mode
1145 *
1146 * This function duplicates a display modes for a connector. Drivers for hardware
1147 * that only supports a single fixed mode can use this function in their connector's
1148 * get_modes helper.
1149 *
1150 * Returns:
1151 * The number of created modes.
1152 */
1153int drm_connector_helper_get_modes_fixed(struct drm_connector *connector,
1154 const struct drm_display_mode *fixed_mode)
1155{
1156 struct drm_device *dev = connector->dev;
1157 struct drm_display_mode *mode;
1158
1159 mode = drm_mode_duplicate(dev, fixed_mode);
1160 if (!mode) {
1161 drm_err(dev, "Failed to duplicate mode " DRM_MODE_FMT "\n",
1162 DRM_MODE_ARG(fixed_mode));
1163 return 0;
1164 }
1165
1166 if (mode->name[0] == '\0')
1167 drm_mode_set_name(mode);
1168
1169 mode->type |= DRM_MODE_TYPE_PREFERRED;
1170 drm_mode_probed_add(connector, mode);
1171
1172 if (mode->width_mm)
1173 connector->display_info.width_mm = mode->width_mm;
1174 if (mode->height_mm)
1175 connector->display_info.height_mm = mode->height_mm;
1176
1177 return 1;
1178}
1179EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed);
1180
1181/**
1182 * drm_connector_helper_get_modes - Read EDID and update connector.
1183 * @connector: The connector
1184 *
1185 * Read the EDID using drm_edid_read() (which requires that connector->ddc is
1186 * set), and update the connector using the EDID.
1187 *
1188 * This can be used as the "default" connector helper .get_modes() hook if the
1189 * driver does not need any special processing. This is sets the example what
1190 * custom .get_modes() hooks should do regarding EDID read and connector update.
1191 *
1192 * Returns: Number of modes.
1193 */
1194int drm_connector_helper_get_modes(struct drm_connector *connector)
1195{
1196 const struct drm_edid *drm_edid;
1197 int count;
1198
1199 drm_edid = drm_edid_read(connector);
1200
1201 /*
1202 * Unconditionally update the connector. If the EDID was read
1203 * successfully, fill in the connector information derived from the
1204 * EDID. Otherwise, if the EDID is NULL, clear the connector
1205 * information.
1206 */
1207 drm_edid_connector_update(connector, drm_edid);
1208
1209 count = drm_edid_connector_add_modes(connector);
1210
1211 drm_edid_free(drm_edid);
1212
1213 return count;
1214}
1215EXPORT_SYMBOL(drm_connector_helper_get_modes);
1216
1217/**
1218 * drm_connector_helper_tv_get_modes - Fills the modes availables to a TV connector
1219 * @connector: The connector
1220 *
1221 * Fills the available modes for a TV connector based on the supported
1222 * TV modes, and the default mode expressed by the kernel command line.
1223 *
1224 * This can be used as the default TV connector helper .get_modes() hook
1225 * if the driver does not need any special processing.
1226 *
1227 * Returns:
1228 * The number of modes added to the connector.
1229 */
1230int drm_connector_helper_tv_get_modes(struct drm_connector *connector)
1231{
1232 struct drm_device *dev = connector->dev;
1233 struct drm_property *tv_mode_property =
1234 dev->mode_config.tv_mode_property;
1235 struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
1236 unsigned int ntsc_modes = BIT(DRM_MODE_TV_MODE_NTSC) |
1237 BIT(DRM_MODE_TV_MODE_NTSC_443) |
1238 BIT(DRM_MODE_TV_MODE_NTSC_J) |
1239 BIT(DRM_MODE_TV_MODE_PAL_M);
1240 unsigned int pal_modes = BIT(DRM_MODE_TV_MODE_PAL) |
1241 BIT(DRM_MODE_TV_MODE_PAL_N) |
1242 BIT(DRM_MODE_TV_MODE_SECAM);
1243 unsigned int tv_modes[2] = { UINT_MAX, UINT_MAX };
1244 unsigned int i, supported_tv_modes = 0;
1245
1246 if (!tv_mode_property)
1247 return 0;
1248
1249 for (i = 0; i < tv_mode_property->num_values; i++)
1250 supported_tv_modes |= BIT(tv_mode_property->values[i]);
1251
1252 if ((supported_tv_modes & ntsc_modes) &&
1253 (supported_tv_modes & pal_modes)) {
1254 uint64_t default_mode;
1255
1256 if (drm_object_property_get_default_value(&connector->base,
1257 tv_mode_property,
1258 &default_mode))
1259 return 0;
1260
1261 if (cmdline->tv_mode_specified)
1262 default_mode = cmdline->tv_mode;
1263
1264 if (BIT(default_mode) & ntsc_modes) {
1265 tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
1266 tv_modes[1] = DRM_MODE_TV_MODE_PAL;
1267 } else {
1268 tv_modes[0] = DRM_MODE_TV_MODE_PAL;
1269 tv_modes[1] = DRM_MODE_TV_MODE_NTSC;
1270 }
1271 } else if (supported_tv_modes & ntsc_modes) {
1272 tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
1273 } else if (supported_tv_modes & pal_modes) {
1274 tv_modes[0] = DRM_MODE_TV_MODE_PAL;
1275 } else {
1276 return 0;
1277 }
1278
1279 for (i = 0; i < ARRAY_SIZE(tv_modes); i++) {
1280 struct drm_display_mode *mode;
1281
1282 if (tv_modes[i] == DRM_MODE_TV_MODE_NTSC)
1283 mode = drm_mode_analog_ntsc_480i(dev);
1284 else if (tv_modes[i] == DRM_MODE_TV_MODE_PAL)
1285 mode = drm_mode_analog_pal_576i(dev);
1286 else
1287 break;
1288 if (!mode)
1289 return i;
1290 if (!i)
1291 mode->type |= DRM_MODE_TYPE_PREFERRED;
1292 drm_mode_probed_add(connector, mode);
1293 }
1294
1295 return i;
1296}
1297EXPORT_SYMBOL(drm_connector_helper_tv_get_modes);